Calling device



Patented Sept. 20, 19277.

NITE sATEs PATENT oFFics.

HERBERT OBERGFE-LL, F RIVER FOREST, ILLINOIS, ASSIGNOR, BY MESNE ASSIGN- MENTS, T0 AUTOMATIC ELECTRIC INC., 0F CHICAGO, ILLINOIS, A CORPORATION or DELAWARE.

CALLING- DEVICE.

Application filed May 15, 1924. Serial No. 713,378.

L The present invention relates in -general to calling devices, and more v particularly to impulse senders yfor automatic telephone systems in which the selector switchesused for building up a connection are directlvely controlled by current impulses sent from a subscrlbers station;y and the object of the invention is to produce an improved.

` mechanism of Ithis character embodying a number of novel features tending to increase its efficiency and enhance its usefulness in practice. N

The invention is illustrated in the accompanying drawings, comprising Figs. 1 to 8, inclusive, which are described below:

Fig. 1 is a projected viewy of different parts of the calling device showing their relation to each other.

Fig. 2 is a front view of the plete.

Fig. 3 isa rear view of Fig. 2.

Figs. 4 to 8, inclusive, show varlous parts of the device, Figs. 6` and 7 being shown double size and in cross section.

rlhe calling device consists `of a cupshaped' frame member 25,' which supports device comthe various mechanisms of the device, in-v cluding the usualifinger hole dial which is operated by means of finger holes 64 distributed: around its periphery. y

In the construction of the device [a spring member 63 having a hole in the mid point thereof for receiving a reduced portion of the hub 27, isiplaced within the cup 25 in the position shown in Fig. 1. A reduced portion of hub 27, shown in Flg. 7, extends through the opening. in spring 63, and through a similaropenmg` 1n the base of the cup and is firmly staked 1n place. A power spring holding member 42 (see Figs.v 3 and 7) slides over the reduced portion of hub 27 and is fastened to the cup 25 by meansof ears 43 and 43', which extend through the base of the cup and through openings in spring 63, these ears being bentover as shown in Figs. 1 and 7. By this means spring member 63 is further secured in place.

the eup member 25. vThis erehed breeket Iprovides a bearing for shaft 59 and also serves as a supporting means for the gover- -nor shaft bearing.

Returning now to Fig. 1, a unit comprising pinion 70 and worm Wheel 71 is in fixed relation on shaft 59. This unit is inserted in place in the device through an opening in the base of member 225, the lower end of shaft 59 extending down through an opening in bracket 57 as illustrated in Fig. 6. A bracket 44 placed within the cup has an extension which serves as a bearing for the upper end of shaft 59. :This bracket has two bosses -49 and 50 which definitely determine its ,location with respect to the cup member 25 and -is held in place by screws 32 and 32 A fiber washer 58, and a gear and ratchet unit 22 comprising ratchet wheel 23 and gear wheel 24 are placed on the hub 27. The thickness of washer 58, the height of hub 27, and the thickness of unit l22 are such that with the unit 22 in place the-top of hub 27 is'not quite flush with the top of the unit.. A fiber washer 21 fits snugly over a large part of shaft 20, as illustrated in Fig. 4. When the shaft 20 and its associated plate 18, to which shaft 20 is staked, are put in place, shaft 20 extends down through and beyond the opening of hub 27. When the above described units are in place, gear wheel 24 meshes withpinion 70 and pawl 35, mounted on the under side of plate 18, engages a tooth of the ratchet- 23. It will be noted `from this that the unit 22 will be frictionally engaged between washers 58and 21. .f

Plate 18 is providedwith an arm form'- ing stopsk 72 and 73, and when this plate is in its normalv position stop 72 engages a fixed stop 33 which is a part vof bracket 44. The rotation of plate 18 in a clocki rounding the upper portion of member 25,

and the tip or bent over ends 26 and 26 of spring member 63 snap over the shoulder 81 Q number dial 15 to hold the Same/in.;

Fig. 1, the arm similar to 29 terminatingv in a linger stop 11. In such a case notch 75 of number dial 15 is the one through out portion of the cup member 25 bent at which the part -forming a finder stop passes.

A. keyed portion 62 on plate 18 is for receiving a similarly shaped keyedopening in the center of linger hole dial 10, which is held in fixed relation to the plate 18 by lmachine screw 9.

An instruction card holding ring 1 is provided with three ears, 2, 3 and 3', respectively, which permit this ring to be snapped in. place on the dial 10 in openings in the dial provided for this purpose. B efore puttingthe ring in place, a celluloid .disk 5, and an instruction card 7,' proyided with notches 6 and 8, respectively, are placed within the ring. The ring 1 is provided with an ear 4 in all respects the same as ears 2,13, and 3', except that it is bent the oppositie way. This ear definitely determines the position of disks 5 and 7.

Referring now to Figs. 3 and 6, a nut 56 having a lshoulder is screwed down on the shaft 59 and an impulse cam 55 is positioned on the shoulder of the nut 56, the cam 55 being held in place by a washer 60 and a nut 61.

The governor 76 is of the well known worm driven type and is supported at one end by a portion of bracket 57, and at the other end by a bearing supported by a cut right angles thereto.

A spring assembly having fixed to it al member provided witharms 51 and 53 is placed on the shaft 20, one end of the spring 82 of the assembly being fixed to the shaft and the other end being fixed to a notch on the previously described member 42. This sprlng assembly `is substantially the s same as that shown and described in a copending application of. Obergfell, Serial No.` 679,517, filed December 10, 1923. When one end of the spring 82 is secured to a notch in member 42 the' same is rotated at least one revolution before fixing` the other end to shaft 2O which is the usual practice in the assembly of this type of calling device. The tension of springy 82 tends Vto rotate the plate `18 in a counter-clockwise direction, which rotation is prevented as previously explained by stop 72 engaging stop 33, and also causes the spring to normally tend to hold the unit 22 and washers 21 and 58 into frictional engagement with each other between member 25 and plate 18 for a purpose which will later be explained.

A. bracket 80, carrying impulse and shunt spring assemblies, and also provided with' a pair of lugs 48 and 48 for securing the dial in a telephone, is held in place on the base of member 25 by machine screws 47 and-47, respectively. When this assembly is in place shunt springs 36, 37 and 38 normally tending to engage each other are prevented from doing so by the cam like arm 51. Im-v pulse springs 40 and 41, which are tensioned to normally extend within range of the im pulse cam 55, are held out of range of this cam by the arm 53 engaging a bushing on the impulse spring 40. A back stop spring 41 determines the normal position of springs 39 and 40 when the `arm 53 is moved away from the bushing on spring 40. In Fig. 3 the spring 41 has been broken away to more clearly show the relation between arm 53 and spring 40, spring 41 being shown in its entirety in Fig.v 5. f y

It will be noted from observation of Fig. 3 that each. shunt and each impulse spring has adjacent it a washer provided with a screw terminal which permits connections to be made with the aid of a screwdriver.

,Also since the bracket- 80 is fastened to member 25, by the simple removal of screws 47 and 47', the calling device less its impulse and shunt springs may be readily removed for repair, etc.

Operation.

Upon the forward rotation of dial 10 plate 18 and shaft 2O are rotated and additional ower is stored in power spring 82. At the eginning of the forward movement of the dial arms 51 and 5.3, being in fixed relation with the shaft 20, move away from' the associated bushings permitting the shunt springs to engagel each other and also permitting the impulse springs to come within range of the impulse cam. rDuring the los forward motion of the dial no part of the gear train is affected, because of the pawl and ratchet connection between plate 18 and the unit 22. .When the dial is released the unit 22 is rot-ated with it and since gear 24 is -in mesh with the pinion 70, this inion, worm wheel 71, and the governor 6 are operated, the governor acting in the usual capacity of maintaining the rate of operation vof the mechanism at a uniform speed, and the impulse cam serving the usual purpose of opening the line c1rcuit extending through the impulse springs 39 and 40 a number of times determined by the number of the di it dialled.

spring d and arm 51 again engages the bushing associated with shunt sprmg 38. During this last half revolution of the impulse cam and just prior to the time cam 55 would ordinarily again operate the imvpulse springs, cam 53 moves them out of sirable to use the calling device without incorporating 'the delay` feature. This may be readily accomplished by simply substituting the bracket 14" (Fig. 8) for the bracket 4A, and by rendering the means for moving the impluse springs out ot range of cam ineffective., This may be readily accomplished in any of several ways, for instance,

- a spring unit having only an arm 51 may' be substituted, arm 53 may be Cut oil, or a spring such as L10 without a bushingmay be used. :l i f When bracket ed" is used its linger stop y 11 is located midway between the designations 1 and 0. rll`his permits the dial to be only operated sutlicient distance to rotate the impulse cam tive revolutions, causing the transmission of ten impulses. llt will, therefore, be seen why the impulse springs d0 and Ll1 must continuously remain within range of the impulse cam when no delay is desired.

ln certain instances itis necessary 'to change number dials. Since the finger hole dial of the present calling device may be putin place and removed without the necessity ot removing the shaft 20, the removal and substitution of number dia-ls is made relatively simple, and is accomplished without atiectingthe adjustment of the operatdit ing mechanism.

ln calling devices of the ratchet type such as disclosed by Keith, Patent No. 1,209,303, reissued December 19, 1916, a hub similar to hub 27 supports a gear and ratchet unit. ln the calling device of the patent the hub 27 extends throughthe unit, which is only connected to thedial by the usual driving. pawl.V ln the patent the normal positionner` the dial is determined by a pin on the dial engaging a tooth of a pinion similar to pinion 70. Now in operating the dial in a careless manner it sometimes loccurs that, since the ratchet and gear unit are free to rotate while the dial is in an off normal, position, suiiicient momentum is set up in the unit to cause it to advance slightly and when the dial reaches normal it engages a tooth of: the pinion even though the pawl other call the calling device springs will be l closed responsive to dialling the digit one or will be closed and then opened once only it the digit two is dialled, etc.

ln the past this above trouble has been overcome to a de ree by tensioning the pawl spring, associate with the dial, very stitiiy, which resulted in noiseness of operation and increased friction between the bottom side of the gear unit and the dial supporting frame. ln order to overcome the increased friction between the unit and the trarne the power spring had to be tension'ed more stiy. The result was a dial which operated not only noisily but stimy.

dln the present callin device, as previously pointed outthe hu 27 does not entend quite through the unit 22, and therefore the power spring 82 in holding the shaft 20 andthe associated plate in place also holds the unit v22 in frictional engagement with plate 18 and member 25 through the medium ofthe ber washers 21 and 58, and any tendency of the unit 22 to run ahead is overcome.

Due to the large surface covered by washers 21 and 58 the tension between plate 18 and member 25 need not be very great# lFur'themore, since the pawl 35 does not en ter into this frictional arrangement its spring may be of very light tension, resulting in quietness ot operation'. These ar-l rangements make it ractical to maintain the normal tensione power spring 82 at a minimum which is reflected by the easy operation of the dial.

The various features and advantages of 'the invention having been described and ascertained, whatl is considered new and is desired to have protected by Letters Patent will be pointed out in the appended claims,l

What is claimed is:

1. 1n an impulse sending device, a finger hole dial, a supporting shaft for said dial, impulse mechanism for said device including a train of ears for operating it, a source of power or operating said train of gears comprising a spring normally tending to rotate said dial, a stop for normally preventing its rotation, a number dial located between said finger hole dial and said mechanism, means for holding said dial in place, and means for removin said number and finger hole dials from sai device while retaining said mechanism, gears, shaft, dial holding means and spring mtact.

2. In an impulse transmitting device, a cam, impulse springs, an impulse cam driving pinion, a gear for driving said pinion, a

` rotatable dial, a ratchet connection between said dial and driving. gear, a power spring 1 for operating said gear and pinion to rotate eil lhole dial rotatable diderent maximum disand one-hall revolutions said cam, means for storing power in said spring, and means including fiber washers for maintaining a lrictional connection betvveen said dial and said gear at all times to prevent any possible over run el said gear and cam. I

3, ln an im ulse transmitting device, a

supporting she l, a number dial, and means hired to said shell for securing said dial thereto, said means comprising a spring member having a. hook at each ot its extreme ends which snap in place over the edge ol the dial when the dial is properly positioned on said shell.

t. ln an impulse transmitting device, a-

rotatable finger holedial, a nger stop tor limiting the distance ol rotation ol said dial, and a second hnger stop which may be substituted lor said rst stop to increase the possible'distance ol rotation el the dial.

5. ln a calling device, a pair ot interchangeable tier stops, a rotatable nger tances dependent on the stop "used, an impulse cam, and mechanism controlled by the angular displacement oil said dial lor ro-,

lon`said sha-llt lor oounicating the operation oil the nger dial to said pinion, and means li'for clamping said unit between trictionalsurfaces in assembling the device to prevent the unit over running the pawl.

` 'l'. ln a calling device, impulse sending4 mechanism, a pinion lor drivmg said mec-hanism, a dinger dial, a plate upon which the device` is assembled, a shalt and a pawl on the dial, a stud on the late having a hole therein lor receiving saiD shalt, a unit gear` and ratchet wheel mounted on said stud and rotatable thereon by means ot said pawl' to counicate the operation ol the dial to the mechanism, said stud being shorter than the unit, and a pair out lrictional washers above and below the unit and clamped against the same to 'preventA tree rotary movement thereoll.

8. lna calling. device, a nger hole,dial,

- impulse sending mechanism, a gear and ratchet train lor operating said mechanism,

a unit consisting ot a shalt carrying a plate at one end lorming a stop to limit the rotary movement ol the dial and having a rpawl mounted on said plate to :una

cate the rotation ol the shalt to said ratchet andfgear train, projectionson the other .end

.of said shaft for ren/dering said impulse cam, a linger hole dial, mechanism con-` trolled by said dial for transmitting rotary movement l to said cam, interchangeable hnger stops limiting the distance ol rotation ol the dial and thereby limiting the lnumber of revolutions of saidcam, one ot said stops permitting the dial to cause the cam to rotate a denite maximum number of revolutions, and the other stop permitting the dial to cause the cam to rotate a smaller maximum' number olf revolutions.

` l0. ln a calling device, a hnger hole dial, an impulse cam rotatable a'number ol revolutions dependent on the angular displacement of said dial, and interchangeable Lnger stops forfsaid dial permitting the possible angular displacement ot said dial to be varied. i

ll. ln an impulse transmitting device, a driving element, a driven element, and means including ber Washers tor maintaining a trictional connection between said elements at all times to prevent any possible over-run ol said `driven element.

l2. ln an impulse transmitting device, a driving element, a driven element, and means lor maintaining aalrictional connection between said elements at allV times.

13. ln a calling device, impulse mechanism, a rotatable element, a second element lor driving said mechanism, a third element lorl communicating the `operation ol the tirst elementto the second element. and trictional means tor preventing the third element from over-rning the rst element.

ll. lin an impulse transmitting device, a cup shaped shell providedvvith aledge at the top thereol, a -number vdial located upon said ledge, and flexible means secured to the base ol said shell -or holding said dial in plac l5. ln an imse transmitting device, al

lli 1|y number dial,'a ger hole dial, impulse and iulse operating mechanism for the device, means tor holding the number dial in place secured to the devicebeilore the hnger hole dial is put in place, and means lor therealter connecting the ger hole -dial to the device. p lb. lin an impulse transmitting device, a number dial, a cup shaped supporting shell having a ledge in the upper edge ot itsvvall lor receiving said dial, and a spring member secured to the base ot .the shell provided vvith derrible extensions lor ly holdin the dial in place..

i7. n an impulse` transmitting device, a supporting shell, a nber dial, a spring member tor holding the dial in place on p. w 70 9. vln a calling device, a rotatable impulse Miti lll@

said shell, a power spring for transmitting motion, and means for holding both said springs in lixed relation to said shell.

18. In an impulse transmitting device, a cup shaped supporting shell, and a linger stop secured Within said shell in Xed relation thereto.

19. In an impulse transmitting device, a main supporting shell, a finger hold dial, a

train ot gears and impulse' mechanism con- 10 trolled by said dial and a linger stop within the shell for limiting the movement of the dial and also serving as a bearing for one of said gears.

In Witness whereof,` I hereunto subscribe 15 my name this 10th day of May, A. D., 1924.

HERBERT F. OBERGFELL. 

